Pneumatic hammer



\May 5, 1925.

n E. W. STEVENS PNEUMATIC HAMMER Filed Aug. 7, 1922 Patented May 5, 1925.

UNITED STATES PATENT OFFICE.

EDWARD W. STEVENS. 0F DETROIT, MICHIGAN, ASSIGNOR TO CHICAGO PNEUMATIC TOOL COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

PNEUMATIC HAMMER.

Application filed August 7, 1922.

To all whom it may concern:

Be it known that I, EDWARD IV. STEVENS, a citizen of the United States, residing at Detroit, in the county of \Vayne and State of lvlichigan. have invented certain new and useful Inrprovements in Pneumatic Hammers, of which the following is a specification.

My invention relates to a pneumatic hammer, more particularly that type known as a long stroke or riveting hammer, and the object thereof is to provide a simple and eliicient means for effectually closing or sealing the rear end of the piston chamber and for preventing the scoring of the valve block or handle due to the act of tightening or loosening the clamping engagement therebetwecn.

Speaking in general terms, my invention consists in a provision of a new kind of gasket, adapted to be clamped between the rear end of the usual valve box and the inner end of the socket portion of the handle and having port openings registering with the ports in the valve block. This gasket is in the form of a disk, which extends across the rear end of the piston chamber formed by the central bore of the valve block, with the result that a perfect cushioning space is provided in the rear end of the piston chamher by the effectual sealing produced by this gasket, and with the further result that scoring or injury to the adjacent surfaces of the handle socket; and valve is prevented. Moreover, by the use of such gasket it is uimecessary to tighten the handle as hard on the cylinder as heretofore, and, furthermore, any slight loosening of the connection between the handle and cylinder will not destroy said air cushion.

In the drawing, Fig. 1 is a longitudinal section of a riveting hammer embodying my invention; Fig. 2 a section on the irregular line 2 2 of Fig. 1; Fig. 3 an elevation of the new form of gasket interposed between the valve block and handle; and Fig. 4 a section on the line t t of Fig. 3.

In the present instance. for the purpose of a clear and definite description of my invention, I have shown such invention embodied in the well-known form of riveting hammer made in accordance with Boyer Patent No. 917,242 issued on April 6th, 1909. Because of the nature of my present inven- Serial No. 579,988.

tion and of the fact that said patent describes in detail the construction and mode of operation, it will suffice to here refer briefly to the structure involved.

As shown, the hammer includes a cylinder 1, a handle 2 having a socket portion 3. a valve block 4, a valve 5, a piston (3 and a rivet set 7. The valve block which is positioned within a socket in the rear end of the cylinder has a central bore and contains the hollow valve The bore of the block and valve form the rearward portion or continuation of the piston chamber 8 of the hammer. This block is provided with the usual series of ports and passages t). The socket portion 3 of the handle is secured upon the rear end of the cylinder and thereby clamps and holds the valve block in position. According to usual practice, the bottom surface of the socket and the rear surface or face of the block abut each other as a result of this clamping operation.

My invention comprises the employment of a gasket in the form of a disk 10 located and clamped between the block and the bottom of the socket 3. This disk is of peculiar and novel construction for the purpose intended. As shown and by preference. this disk has its central part 11 extended or dished forwardly so as to fit slightly and accurately within the central bore of the rear end of the block to thereby incr aise the sealing effect and also to properly loc; te the disk with respect to the block. The disk i also provided with a series of ports 12 cm responding to and registering with the ports and passages S) in the valve block. The disk is provided with one or more projections 13 extending forwardly and adapted to engage the block, preferably in one or more of the port openings 9 thereof. As shown, there are two of these projections 13 and the same are formed in practice by punching in a forward direction the metal from two opposite ports 14. These projections 13 engage two of the ports 9 of the valve block as shown in Fig. 1. By these means the gasket is prevented from rotating, which would have the effect of cutting off the free passage of the live air to the ports and passages of the block. The gasket may be made of any suitable material but by preference and as a matter of practice, I employ a soft or compressible metal such as copper.

I claim 1,. A pneumatic hammer including a cylinder having a piston cham'l'ier, a valve block located in the rear end of the cylinder and having a central bore, a hollow valve in such block, said bore and valve forming the rear end of the piston chamber, a handle having a socket secured to the cylinder and clamping the block in place, and a gasket arranged between the rear end of the block and handle socket and closing the rear end of the piston chamber, said block having a series of ports and said gasket having a corresponding series of ports registering therewith and provided with a projection to engage one of the ports in the block,

2. A pneumatic hammer including a cylinder having a piston chamber, a valve block located in the rear end of the cylinder and having a central bore, a hollow valve in such block, said bore and valve forming the rear end of the piston chamber, a handle having a socket secured to the cylinder and clamping the block in place, and a gasket arranged between the rear end of the block and handle socket and closing the rear end of the piston chamber, said block having a series of ports and said gasket having a corresponding series of ports registering therewith, and provided at one of its ports with a forwardly extending projection to engage one of the ports in the valve block.

3. A pneumatic hammer including a cylinder having a piston chamber, a valve block located in the rear end of the cylinder and having a central bore, a hollow valve in such block, said bore and valve forming the rear end of the piston chamber, a handle having a socket secured to the cylinder and clamping the block in place, and a gasket arranged between the rear end of the block and handle socket and closing the rear end of the piston chamber, said block having a series 0-1 ports and said gasket having a corresponding series of sports registering therewith. and provided at two opposite ports with torvvardly extending projections to engage two ports in the valve block.

t. A pneumatic hammer including a cylinder having a piston chamber, a valve block member in one end of said cylinder and having a central bore, a hollow valve in said block defining with said bore the rear end of the piston chamber, a handle having a socket portion secured to the cylinder and clamping the block member in place, and a gasket member interposed between said block member and said handle and closing the rear of the piston chamber, both said members having corresponding series of ports for the passage of motive fluid. and means on one of said members cooperating with one of the ports on the other member for maintaining the ports of both members in register.

A gasket adapted for insertion between the valve block and the handle socket of a sleeve valve type of pneumatic tool to seal the piston chamber thereof, said gasket having ports corresponding to the ports in the valve block and a projection adapted to cooperate with one of the ports in the valve block to maintain the ports of the gasket and block in register.

(3. A gasket adapted for insertion between the valve block and the handle socket of a sleeve valvc type of pneumatic tool to seal the piston chamber thereof, said gasket being of sheet material having ports corresponding to the ports in the valve block and an inte 'ral projection adapted to engage one of the ports in the valve block to maintain the ports of the gasket and block in register.

7. A gasket adapted for insertion between the valve block and the handle socket of a sleeve valve type of pneumatic tool to seal the piston chamber thereof, said gasket being of relatively soft sheet metal dished to tit the bore of the valve block, said gasket having ports cor-responding to the ports in the valve block and astruck-up projecting portion for cooperation with one of the valve block ponts to maintain the gasket 1n proper register with the valve block.

EDW ARD V. STIE\' ENS. 

